AES E-Library

Watermark-Aided Pre-Echo Reduction in Low Bit-Rate Audio Coding

Low bit-rate coding/decoding with standard AAC and MP3 coders smoothes attacks in transient signals and increases the pre-echo. A system is proposed for reducing pre-echo artifacts by embedding temporal envelope correction as watermarking data, which eliminates the need for an auxiliary communications channel. The restored signal is reconstructed at the receiver from two components: the decoded signal generated by the core decoder, and the temporal envelope of the original signal, which is represented by a few parameters that are transmitted as embedded data in the audio signal.